The present invention relates to a photovoltaic module which is distinguished by a special series connection of solar cells on a carrier substrate. In order to make this possible, an insulating layer must be present, said insulating layer being produced by a diode in the case of the invention. In the photovoltaic module, this diode serves at the same time as protective or bypass diode. In this case, two functions are hence integrated in one system, which leads to significant advantages in cost.
In photovoltaics, normally a plurality of solar cells are combined to form large units (arrays, modules). Within one array, a plurality of solar cells are thereby connected either in parallel or in series. For this purpose, an electrical conductive connection of one to the next solar cell is required. It is also known in the state of the art to use bypass diodes in modules or arrays for the protection of the solar cells. This is necessary since it can occur that individual solar cells within one module are subjected to a voltage in the stop band, which would lead to the destruction of these solar cells.
A special field of photovoltaics is the so-called “concentrator photovoltaics”, in which sunlight is concentrated by means of an optical system (e.g. lens, mirror) and the concentrated light beam impinges on a relatively small solar cell—according to the type of unit. Because of the light concentration, heat is produced locally which must be dissipated. According to the system, this is effected passively or by active cooling, e.g. by means of water.
The state of the art for series connection of solar cells in such a concentrator module is described by J. Jaus (J. Jaus, U. Fleischfresser, G. Peharz, F. Dimroth, H. Lerchenmüller, A. W. Bett, “HEAT SINK-SUBSTRATES FOR AUTOMATED ASSEMBLY OF CONCENTRATOR-MODULES”, Proc. of 21st European Photovoltaic Conference and Exhibition, Dresden, September 2006, to be published). In this publication, the so-called prepreg technology and also the use of copper plates with gold-plated circuit boards is presented in detail. However this known technology has the following disadvantages:                According to the technology, a fairly large number of individual parts is required, for which costs arise in production and also in storage and manufacturing logistics.        In the assembly of the individual parts, many operating steps occur, “preparation of the surfaces”, “application of connecting materials (adhesive, solder)”, “gripping and positioning part”, “setting of the adhesive layers” or “implementing the soldering process”, frequently even further process-accompanying steps.        This large number of operating steps increases the cycle times, lowers the throughput of the production line and increases the material expenditure. Consequently high costs are ultimately incurred.        Individual steps, such as e.g. contacting of the individual solar cell chips, incur high process costs (soldering process) and handling costs.        Prepreg technology has proved in practice to be susceptible to faults: during production, burrs are produced which can lead to short circuits. This makes complex tests necessary and the individual prepregs comparatively expensive.        
However photovoltaic modules must be produced economically. In order to be able to achieve low costs, the number of components to be assembled must be low and the components themselves should be economical at the same time. In particular the assumption of a plurality of functionalities in one component helps to reduce costs.